How Drone-Delivered Peanut Butter Treats Could Save This Endangered Ferret

As early as this fall, prairie dogs in Montana could experience a magical phenomenon unlike anything they've ever witnessed: tasty, bite-sized, peanut butter treats falling from the heavens like drops of rain.

What the prairie dogs won't know is that these treats are being strategically administered by aerial drones manned by conservationists at US Fish and Wildlife Services. And they aren't just a tasty snack, but a specially-designed vaccine intended to keep the prairie dogs plague-free—so that black-footed ferrets can kill and eat them. Don't tell the prairie dogs.

"It's basically a contraption that would be attached to the bottom of the drone and it would spin and, at a periodic rate, pop out these bait in various directions," said Ryan Moehring, a public affairs specialist at Fish and Wildlife Services' Mountain Prairie region, describing the device designed to dole out the vaccine-laced treats.

Sylvatic plague is an infectious bacterial disease spread by fleas. It's very deadly to these animals: A single outbreak can kill 90 percent of a prairie dog colony. Moehring told me it's also considered the biggest remaining hurdle to the conservation of another prairie dweller: the endangered black-footed ferret.

The black-footed ferret has flirted with extinction more than once over the last few decades, with the population dwindling to just 18 ferrets on the whole planet by the early 80s. Captive breeding efforts (including artificially inseminating ferrets with semen frozen from those 1980s ferrets) have brought the population up to 300 living in captivity, and now conservationists are working to establish a sustainable wild population.

There are "a few hundred" black-footed ferrets across 24 sites in North America, Moehring told me, but their survival relies heavily on the prairie dogs—an animal that, though it also faces threats like habitat loss and disease, has got a comparatively healthier population size. Black-footed ferrets not only eat prairie dogs, but they also live in their burrows. Protecting the prairie dogs from plague will help keep them alive and well to serve as prey for the endangered black-footed ferret.

"I always joke that black-footed ferrets are the worst possible neighbors," Moehring said. "They come in, eat you, and steal your home. But we love them. They're cute and they have such great personalities."

Aside from their darling features, black-footed ferrets are also a key player in their ecosystem. They're considered a flagship species for the American prairies, and their conservation helps protect as many as 130 other plant and animal species. That's why the plague threatening to wipe out prairie dogs—the ferrets' main source of food and shelter—is such a problem.

An oral vaccine against the sylvatic plague was developed for prairie dogs more than a decade ago, and it's been through clinical trials with great success. It was safe, prairie dogs loved the peanut butter treats used to deliver the vaccine, and it was highly effective.

Now, FWS wants to roll out a more extensive program, distributing vaccine-laden treats over as many as 10,000 acres of prairie dog colonies at a rate of 50 pieces of bait per acre. They've proposed two possible ways to do this: manually, with workers out on foot or ATV tossing the bait by hand, or via drone. Though both methods have passed environmental assessment, Moehring told me it's up to senior management officials to sign off on which route to take.

"There are some folks that really want to use the drones," Moehring told me. Aside from being more efficient, drones would be minimally disruptive.

"These four-wheelers driving over the terrain, rolling over the top of vegetation. It can be disruptive. Using the drone would obviously not impact any of the local vegetation on the ground, or any of the local fauna. We think, in theory, it would be less disruptive [than manual baiting]," he said.

Moehring said the program could begin as early as this fall, but deciding how to dole out peanut butter treats to prairie dogs is not the only thing on FWS's plate, so it could take longer for a decision to be made. Either way, a few thousand lucky prairie dogs are in for a treat—at least until they become the treat for their nasty neighbors.